A method of the kind described in the opening paragraph is known from European Patent Application No. EP-A 0 338 157, according to which the capacitor is formed in that the following materials are successively provided and given the correct shape on the surface of a silicon body: a first layer of platinum used as a lower electrode, a layer of ferroelectric material used as a dielectric material, and a second layer of platinum used as an upper electrode. A perovskite-type material is used as the ferroelectric material, such as lead-zirconium titanate.
For reasons of economy the tendency is to realise as many memory elements as possible per unit area on a semiconductor body. This means in practice that the space on the semiconductor body must be utilized as efficiently as possible. For this purpose, the capacitor must have comparatively small dimensions with the thinnest possible dielectric material. When platinum is provided on silicon oxide or nitride, the lower electrode shows insufficient adhesion to the surface. It is also found that contamination of the thin dielectric material with electrode metal can occur in the known method, and consequently electrical breakdown is possible in the dielectric material. The memory then turns out to be unreliable for these reasons.